<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8"> 
    <!-- <meta http-equiv="refresh" content="3" charset='UTF-8'>  -->
    <title>Java后端WebSocket的Tomcat实现</title>
    	<!--使用veu开发前端-->
	<script src="https://cdn.staticfile.org/vue/2.4.2/vue.min.js"></script>
    <script src="https://cdn.staticfile.org/axios/0.18.0/axios.min.js"></script>

     <!-- 使用bootStrap引入文件时需要注意顺序，最好按照以下顺序引入 -->
    <link rel="stylesheet" type="text/css" href="css/bootstrap.min.css">
    <script type="text/javascript" src="js/jquery.min.js"></script>
    <script type="text/javascript" src="js/popper.min.js"></script>
    <script type="text/javascript" src="js/bootstrap.min.js"></script>
</head>
<body>
<span id="aa"></span>
Welcome<br/>
<input id="text" type="text"/>
<button onclick="send()">发送消息</button> 
<hr/>
<button onclick="closeWebSocket()">关闭WebSocket连接</button>
<hr/>
<div id="message"></div> 
</body>
 
<script type="text/javascript">
    var websocket = null;
    //判断当前浏览器是否支持WebSocket
    if ('WebSocket' in window) {
        websocket = new WebSocket('ws://localhost:8080/websocket');
    }
    else {
        alert('当前浏览器 Not support websocket')
    }
 
    //连接发生错误的回调方法
    websocket.onerror = function () {
        setMessageInnerHTML("WebSocket连接发生错误");
    };
 
    //连接成功建立的回调方法
    websocket.onopen = function (event) {
        setMessageInnerHTML("WebSocket连接成功");         
    }
    //设置定时器，刷新当前在线人数
      setTimeout(
    		 function(){
    			 window.location
    	 axios.get('http://localhost:8080/webSocketTest.html').then(res =>{
    		 
    	 })
     },1000);  
    //接收到消息的回调方法
    websocket.onmessage = function (event) {
        setMessageInnerHTML(event.data);
        console.info(event);

    }
    
    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML){
        document.getElementById('aa').innerHTML += innerHTML + '<br/>';
    }
 
    //连接关闭的回调方法
    websocket.onclose = function () {
        setMessageInnerHTML("WebSocket连接关闭");
    }
 
    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
        closeWebSocket();
    }
 
    //关闭WebSocket连接
    function closeWebSocket() {
        websocket.close();
    }
 
    //发送消息
    function send() {
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
</script>
</html>